Burglar-alarm.



PATENTBD NOV. 12, 1907.

H. R. LASSEN.

BURGLAR ALARM.

APPLICATION mum in 21. 1001.

UNITED STATES PATENT OFFICE.

BURGLAR-ALARM.

Specification of Letters Patent.

Patented Nov. 12, 1907.

Application filed May 21, 1907. Serial No. 374,850-

To all whom it may concern:

Be it known that I, I'IERMANN RUDOLPH LASSEN, a subject of the German Emperor, and resident of No. 58 Admiralitatstrasse, Hamburg, Germany, have invented certain new and useful Improvements in and Relating to Burglar-Alarms, of which the following is a specification.

The present invention relates to improvements in a burglar alarm which, the moment the wire or thread is pulled, would cause a bell to ring continuously, even after the cause which influenced or moved the thread is removed, so that it will never fail in directing attention.

The accompanying drawing gives a perspective representation of the device.

In the devices of the kind known, employed for making alarm during the advent of thieves or the like, there is the disadvantage of the bell ceasing to ring the instant the cause which influenced the thread has been removed. This disadvantage is obviated in the present invention by an arrangement which will cause the bell to ring continuously until stopped.

The device consists of a box or a frame a in which two springs d, d and a weight 6 is arranged. The springs are connected with an electrical circuit in such a way that when the circuit is closed, by a contact of the weight, a bell begins to ring continuously. This effect is derived by the said weight e, which is of metal and suspended by a thread between the said two springs, falling upon the latter when the thread is broken, and closes the circuit.

In order to insure the bell ringing or causing alarm even in the event the'thread is uncut but only pulled and the cause which influenced the thread is removed, the weight a is provided with a ledge g which is adapted to catch and hang on the upper edge of the spring d in such a manner that the weight comes in contact with the spring d and closes the circuit. In this latter case the bell can be stopped ringing only by setting the spring d backwards and releasing the weight for which a rod h is attached at the back of the spring and owing to the springs and the weight being made of a conducting material, further contacts, for closing the circuit, are superfluous.

I claim In a device for burglar alarm, the combination, a frame, two flat springs vertically affixed by the middle in the frame opposite to each other with their ends bent inwardly and put in connection with a circuit, a weight movahly suspended by a thread between the said two springs being adapted to close the circuit between the upper and the lower ends of the said springs, a ledge on the said weight being adapted to catch and hang on one of the upper edges of the springs and close the circuit for causing a hell to ring continuously, and the means to relieve the spring of the weight consisting in a rod which is attached to the spring, substantially as described.

I-IERMANN RUDOLPH LASSEN.

Witnesses J. A. Nuns, M. Piis'ron. 

